Approximate Equivalent Hardness Numbers for Wrought Coppers (>99% Cu, alloys C10200 through C14200)
Rockwell Hardness Number Brinell Hardness Number B scale, 100 kgf,
1/16 in. (1.588 mm) ball,
HRBF scale, 60 kgf,
1/16 in. (1.588 mm) ball,
HRF500 kgf,
10 mm diameter ball
HBS0.04 in. (1.02 mm) strip and greater
0.08 in. (2.03 mm) strip 67 99.0 -- 66 98.0 -- 65 97.0 120 64 96.0 117.5 62.5 95.5 115.0 61.0 95.0 112.0 59.5 94.0 110.0 58.5 93.0 107.0 57.0 92.5 105.0 55.0 91.5 102.0 53.5 91.0 99.5 52.0 90.5 97.0 50.0 89.5 94.5 48.0 88.5 92.0 46.5 87.5 89.5 44.5 87.0 87.0 42.0 85.5 84.5 40.0 84.5 82.0 38.0 83.0 79.5 35.5 82.0 77.0 33.0 81.0 74.5 30.5 79.5 28.0 78.0 25.5 76.5 23.0 74.5 20.0 73.0 17.0 71.0 14.5 69.0 11.5 67.5 8.5 66.0 5.0 64.0 2.0 62.0 Source: ASTM E140